Thursday, February 8, 2001
Quiz 3
Name: _______________________________
A judgment is objective if its
outcome does not depend on the judge; taste of coffee
vs. validity of argument. (Lecture).
An argument is formal if the validity of the argument does not
depend on the meaning of the symbols employed. (Handout #5).
From the assumption `not A' and the derivation of a contradiction you
infer `A'. (Lecture)
not A
:
:
Contradiction
---------
A
You know nothing, the argument could as well
be invalid. (Lecture)
The argument is not valid. Because it is
possible for the premises to be true, but the conclusion to be
false, for example, if my income rises because of a raise and
not because of the lowering of my taxes. (Lecture)